Even the noblest planet lovers sometimes crater to the convenience of single-use water bottles. Reusable empties demand serious real estate in your tote or backpack, and if you wanted to go hands-free? Not an option. Enter the Vapur Anti-bottle ($14 at Exit 9, 51 Ave. A, nr. 3rd St.; 212-228-0145). The dishwasher-safe, BPA-free plastic vessel is sturdy when full, but rolls or folds flat when empty so you can stuff it in your back pocket or shove it so deep into your bag you’ll forget about it until the next time you get thirsty.